Get rid of the built-in copy of LZ4

On Linux or BSD distributions we have a native version installed
via package manager. On Windows, we can just build it from source
like the other libraries.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

1 files changed, 0 insertions, 1343 deletions

diff --git a/lib/lz4/lz4hc.c b/lib/lz4/lz4hc.c
deleted file mode 100644
index 4bdf96e..0000000
--- a/lib/lz4/lz4hc.c
+++ /dev/null
@@ -1,1343 +0,0 @@
-/*
-    LZ4 HC - High Compression Mode of LZ4
-    Copyright (C) 2011-2017, Yann Collet.
-
-    BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
-
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions are
-    met:
-
-    * Redistributions of source code must retain the above copyright
-    notice, this list of conditions and the following disclaimer.
-    * Redistributions in binary form must reproduce the above
-    copyright notice, this list of conditions and the following disclaimer
-    in the documentation and/or other materials provided with the
-    distribution.
-
-    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-    You can contact the author at :
-       - LZ4 source repository : https://github.com/lz4/lz4
-       - LZ4 public forum : https://groups.google.com/forum/#!forum/lz4c
-*/
-/* note : lz4hc is not an independent module, it requires lz4.h/lz4.c for proper compilation */
-
-
-/* *************************************
-*  Tuning Parameter
-***************************************/
-
-/*! HEAPMODE :
- *  Select how default compression function will allocate workplace memory,
- *  in stack (0:fastest), or in heap (1:requires malloc()).
- *  Since workplace is rather large, heap mode is recommended.
- */
-#ifndef LZ4HC_HEAPMODE
-#  define LZ4HC_HEAPMODE 1
-#endif
-
-
-/*===    Dependency    ===*/
-#define LZ4_HC_STATIC_LINKING_ONLY
-#include "lz4hc.h"
-
-
-/*===   Common LZ4 definitions   ===*/
-#if defined(__GNUC__)
-#  pragma GCC diagnostic ignored "-Wunused-function"
-#endif
-#if defined (__clang__)
-#  pragma clang diagnostic ignored "-Wunused-function"
-#endif
-
-/*===   Enums   ===*/
-typedef enum { noDictCtx, usingDictCtxHc } dictCtx_directive;
-
-
-#define LZ4_COMMONDEFS_ONLY
-#ifndef LZ4_SRC_INCLUDED
-#include "lz4.c"   /* LZ4_count, constants, mem */
-#endif
-
-/*===   Constants   ===*/
-#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
-#define LZ4_OPT_NUM   (1<<12)
-
-
-/*===   Macros   ===*/
-#define MIN(a,b)   ( (a) < (b) ? (a) : (b) )
-#define MAX(a,b)   ( (a) > (b) ? (a) : (b) )
-#define HASH_FUNCTION(i)         (((i) * 2654435761U) >> ((MINMATCH*8)-LZ4HC_HASH_LOG))
-#define DELTANEXTMAXD(p)         chainTable[(p) & LZ4HC_MAXD_MASK]    /* flexible, LZ4HC_MAXD dependent */
-#define DELTANEXTU16(table, pos) table[(U16)(pos)]   /* faster */
-/* Make fields passed to, and updated by LZ4HC_encodeSequence explicit */
-#define UPDATABLE(ip, op, anchor) &ip, &op, &anchor
-
-static U32 LZ4HC_hashPtr(const void* ptr) { return HASH_FUNCTION(LZ4_read32(ptr)); }
-
-
-/**************************************
-*  HC Compression
-**************************************/
-static void LZ4HC_clearTables (LZ4HC_CCtx_internal* hc4)
-{
-    MEM_INIT((void*)hc4->hashTable, 0, sizeof(hc4->hashTable));
-    MEM_INIT(hc4->chainTable, 0xFF, sizeof(hc4->chainTable));
-}
-
-static void LZ4HC_init_internal (LZ4HC_CCtx_internal* hc4, const BYTE* start)
-{
-    uptrval startingOffset = (uptrval)(hc4->end - hc4->base);
-    if (startingOffset > 1 GB) {
-        LZ4HC_clearTables(hc4);
-        startingOffset = 0;
-    }
-    startingOffset += 64 KB;
-    hc4->nextToUpdate = (U32) startingOffset;
-    hc4->base = start - startingOffset;
-    hc4->end = start;
-    hc4->dictBase = start - startingOffset;
-    hc4->dictLimit = (U32) startingOffset;
-    hc4->lowLimit = (U32) startingOffset;
-}
-
-
-/* Update chains up to ip (excluded) */
-LZ4_FORCE_INLINE void LZ4HC_Insert (LZ4HC_CCtx_internal* hc4, const BYTE* ip)
-{
-    U16* const chainTable = hc4->chainTable;
-    U32* const hashTable  = hc4->hashTable;
-    const BYTE* const base = hc4->base;
-    U32 const target = (U32)(ip - base);
-    U32 idx = hc4->nextToUpdate;
-
-    while (idx < target) {
-        U32 const h = LZ4HC_hashPtr(base+idx);
-        size_t delta = idx - hashTable[h];
-        if (delta>LZ4_DISTANCE_MAX) delta = LZ4_DISTANCE_MAX;
-        DELTANEXTU16(chainTable, idx) = (U16)delta;
-        hashTable[h] = idx;
-        idx++;
-    }
-
-    hc4->nextToUpdate = target;
-}
-
-/** LZ4HC_countBack() :
- * @return : negative value, nb of common bytes before ip/match */
-LZ4_FORCE_INLINE
-int LZ4HC_countBack(const BYTE* const ip, const BYTE* const match,
-                    const BYTE* const iMin, const BYTE* const mMin)
-{
-    int back = 0;
-    int const min = (int)MAX(iMin - ip, mMin - match);
-    assert(min <= 0);
-    assert(ip >= iMin); assert((size_t)(ip-iMin) < (1U<<31));
-    assert(match >= mMin); assert((size_t)(match - mMin) < (1U<<31));
-    while ( (back > min)
-         && (ip[back-1] == match[back-1]) )
-            back--;
-    return back;
-}
-
-#if defined(_MSC_VER)
-#  define LZ4HC_rotl32(x,r) _rotl(x,r)
-#else
-#  define LZ4HC_rotl32(x,r) ((x << r) | (x >> (32 - r)))
-#endif
-
-
-static U32 LZ4HC_rotatePattern(size_t const rotate, U32 const pattern)
-{
-    size_t const bitsToRotate = (rotate & (sizeof(pattern) - 1)) << 3;
-    if (bitsToRotate == 0)
-        return pattern;
-    return LZ4HC_rotl32(pattern, (int)bitsToRotate);
-}
-
-/* LZ4HC_countPattern() :
- * pattern32 must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!) */
-static unsigned
-LZ4HC_countPattern(const BYTE* ip, const BYTE* const iEnd, U32 const pattern32)
-{
-    const BYTE* const iStart = ip;
-    reg_t const pattern = (sizeof(pattern)==8) ? (reg_t)pattern32 + (((reg_t)pattern32) << 32) : pattern32;
-
-    while (likely(ip < iEnd-(sizeof(pattern)-1))) {
-        reg_t const diff = LZ4_read_ARCH(ip) ^ pattern;
-        if (!diff) { ip+=sizeof(pattern); continue; }
-        ip += LZ4_NbCommonBytes(diff);
-        return (unsigned)(ip - iStart);
-    }
-
-    if (LZ4_isLittleEndian()) {
-        reg_t patternByte = pattern;
-        while ((ip<iEnd) && (*ip == (BYTE)patternByte)) {
-            ip++; patternByte >>= 8;
-        }
-    } else {  /* big endian */
-        U32 bitOffset = (sizeof(pattern)*8) - 8;
-        while (ip < iEnd) {
-            BYTE const byte = (BYTE)(pattern >> bitOffset);
-            if (*ip != byte) break;
-            ip ++; bitOffset -= 8;
-        }
-    }
-
-    return (unsigned)(ip - iStart);
-}
-
-/* LZ4HC_reverseCountPattern() :
- * pattern must be a sample of repetitive pattern of length 1, 2 or 4 (but not 3!)
- * read using natural platform endianess */
-static unsigned
-LZ4HC_reverseCountPattern(const BYTE* ip, const BYTE* const iLow, U32 pattern)
-{
-    const BYTE* const iStart = ip;
-
-    while (likely(ip >= iLow+4)) {
-        if (LZ4_read32(ip-4) != pattern) break;
-        ip -= 4;
-    }
-    {   const BYTE* bytePtr = (const BYTE*)(&pattern) + 3; /* works for any endianess */
-        while (likely(ip>iLow)) {
-            if (ip[-1] != *bytePtr) break;
-            ip--; bytePtr--;
-    }   }
-    return (unsigned)(iStart - ip);
-}
-
-/* LZ4HC_protectDictEnd() :
- * Checks if the match is in the last 3 bytes of the dictionary, so reading the
- * 4 byte MINMATCH would overflow.
- * @returns true if the match index is okay.
- */
-static int LZ4HC_protectDictEnd(U32 const dictLimit, U32 const matchIndex)
-{
-    return ((U32)((dictLimit - 1) - matchIndex) >= 3);
-}
-
-typedef enum { rep_untested, rep_not, rep_confirmed } repeat_state_e;
-typedef enum { favorCompressionRatio=0, favorDecompressionSpeed } HCfavor_e;
-
-LZ4_FORCE_INLINE int
-LZ4HC_InsertAndGetWiderMatch (
-    LZ4HC_CCtx_internal* hc4,
-    const BYTE* const ip,
-    const BYTE* const iLowLimit,
-    const BYTE* const iHighLimit,
-    int longest,
-    const BYTE** matchpos,
-    const BYTE** startpos,
-    const int maxNbAttempts,
-    const int patternAnalysis,
-    const int chainSwap,
-    const dictCtx_directive dict,
-    const HCfavor_e favorDecSpeed)
-{
-    U16* const chainTable = hc4->chainTable;
-    U32* const HashTable = hc4->hashTable;
-    const LZ4HC_CCtx_internal * const dictCtx = hc4->dictCtx;
-    const BYTE* const base = hc4->base;
-    const U32 dictLimit = hc4->dictLimit;
-    const BYTE* const lowPrefixPtr = base + dictLimit;
-    const U32 ipIndex = (U32)(ip - base);
-    const U32 lowestMatchIndex = (hc4->lowLimit + (LZ4_DISTANCE_MAX + 1) > ipIndex) ? hc4->lowLimit : ipIndex - LZ4_DISTANCE_MAX;
-    const BYTE* const dictBase = hc4->dictBase;
-    int const lookBackLength = (int)(ip-iLowLimit);
-    int nbAttempts = maxNbAttempts;
-    U32 matchChainPos = 0;
-    U32 const pattern = LZ4_read32(ip);
-    U32 matchIndex;
-    repeat_state_e repeat = rep_untested;
-    size_t srcPatternLength = 0;
-
-    DEBUGLOG(7, "LZ4HC_InsertAndGetWiderMatch");
-    /* First Match */
-    LZ4HC_Insert(hc4, ip);
-    matchIndex = HashTable[LZ4HC_hashPtr(ip)];
-    DEBUGLOG(7, "First match at index %u / %u (lowestMatchIndex)",
-                matchIndex, lowestMatchIndex);
-
-    while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) {
-        int matchLength=0;
-        nbAttempts--;
-        assert(matchIndex < ipIndex);
-        if (favorDecSpeed && (ipIndex - matchIndex < 8)) {
-            /* do nothing */
-        } else if (matchIndex >= dictLimit) {   /* within current Prefix */
-            const BYTE* const matchPtr = base + matchIndex;
-            assert(matchPtr >= lowPrefixPtr);
-            assert(matchPtr < ip);
-            assert(longest >= 1);
-            if (LZ4_read16(iLowLimit + longest - 1) == LZ4_read16(matchPtr - lookBackLength + longest - 1)) {
-                if (LZ4_read32(matchPtr) == pattern) {
-                    int const back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr) : 0;
-                    matchLength = MINMATCH + (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit);
-                    matchLength -= back;
-                    if (matchLength > longest) {
-                        longest = matchLength;
-                        *matchpos = matchPtr + back;
-                        *startpos = ip + back;
-            }   }   }
-        } else {   /* lowestMatchIndex <= matchIndex < dictLimit */
-            const BYTE* const matchPtr = dictBase + matchIndex;
-            if (LZ4_read32(matchPtr) == pattern) {
-                const BYTE* const dictStart = dictBase + hc4->lowLimit;
-                int back = 0;
-                const BYTE* vLimit = ip + (dictLimit - matchIndex);
-                if (vLimit > iHighLimit) vLimit = iHighLimit;
-                matchLength = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
-                if ((ip+matchLength == vLimit) && (vLimit < iHighLimit))
-                    matchLength += LZ4_count(ip+matchLength, lowPrefixPtr, iHighLimit);
-                back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictStart) : 0;
-                matchLength -= back;
-                if (matchLength > longest) {
-                    longest = matchLength;
-                    *matchpos = base + matchIndex + back;   /* virtual pos, relative to ip, to retrieve offset */
-                    *startpos = ip + back;
-        }   }   }
-
-        if (chainSwap && matchLength==longest) {    /* better match => select a better chain */
-            assert(lookBackLength==0);   /* search forward only */
-            if (matchIndex + (U32)longest <= ipIndex) {
-                int const kTrigger = 4;
-                U32 distanceToNextMatch = 1;
-                int const end = longest - MINMATCH + 1;
-                int step = 1;
-                int accel = 1 << kTrigger;
-                int pos;
-                for (pos = 0; pos < end; pos += step) {
-                    U32 const candidateDist = DELTANEXTU16(chainTable, matchIndex + (U32)pos);
-                    step = (accel++ >> kTrigger);
-                    if (candidateDist > distanceToNextMatch) {
-                        distanceToNextMatch = candidateDist;
-                        matchChainPos = (U32)pos;
-                        accel = 1 << kTrigger;
-                    }
-                }
-                if (distanceToNextMatch > 1) {
-                    if (distanceToNextMatch > matchIndex) break;   /* avoid overflow */
-                    matchIndex -= distanceToNextMatch;
-                    continue;
-        }   }   }
-
-        {   U32 const distNextMatch = DELTANEXTU16(chainTable, matchIndex);
-            if (patternAnalysis && distNextMatch==1 && matchChainPos==0) {
-                U32 const matchCandidateIdx = matchIndex-1;
-                /* may be a repeated pattern */
-                if (repeat == rep_untested) {
-                    if ( ((pattern & 0xFFFF) == (pattern >> 16))
-                      &  ((pattern & 0xFF)   == (pattern >> 24)) ) {
-                        repeat = rep_confirmed;
-                        srcPatternLength = LZ4HC_countPattern(ip+sizeof(pattern), iHighLimit, pattern) + sizeof(pattern);
-                    } else {
-                        repeat = rep_not;
-                }   }
-                if ( (repeat == rep_confirmed) && (matchCandidateIdx >= lowestMatchIndex)
-                  && LZ4HC_protectDictEnd(dictLimit, matchCandidateIdx) ) {
-                    const int extDict = matchCandidateIdx < dictLimit;
-                    const BYTE* const matchPtr = (extDict ? dictBase : base) + matchCandidateIdx;
-                    if (LZ4_read32(matchPtr) == pattern) {  /* good candidate */
-                        const BYTE* const dictStart = dictBase + hc4->lowLimit;
-                        const BYTE* const iLimit = extDict ? dictBase + dictLimit : iHighLimit;
-                        size_t forwardPatternLength = LZ4HC_countPattern(matchPtr+sizeof(pattern), iLimit, pattern) + sizeof(pattern);
-                        if (extDict && matchPtr + forwardPatternLength == iLimit) {
-                            U32 const rotatedPattern = LZ4HC_rotatePattern(forwardPatternLength, pattern);
-                            forwardPatternLength += LZ4HC_countPattern(lowPrefixPtr, iHighLimit, rotatedPattern);
-                        }
-                        {   const BYTE* const lowestMatchPtr = extDict ? dictStart : lowPrefixPtr;
-                            size_t backLength = LZ4HC_reverseCountPattern(matchPtr, lowestMatchPtr, pattern);
-                            size_t currentSegmentLength;
-                            if (!extDict && matchPtr - backLength == lowPrefixPtr && hc4->lowLimit < dictLimit) {
-                                U32 const rotatedPattern = LZ4HC_rotatePattern((U32)(-(int)backLength), pattern);
-                                backLength += LZ4HC_reverseCountPattern(dictBase + dictLimit, dictStart, rotatedPattern);
-                            }
-                            /* Limit backLength not go further than lowestMatchIndex */
-                            backLength = matchCandidateIdx - MAX(matchCandidateIdx - (U32)backLength, lowestMatchIndex);
-                            assert(matchCandidateIdx - backLength >= lowestMatchIndex);
-                            currentSegmentLength = backLength + forwardPatternLength;
-                            /* Adjust to end of pattern if the source pattern fits, otherwise the beginning of the pattern */
-                            if ( (currentSegmentLength >= srcPatternLength)   /* current pattern segment large enough to contain full srcPatternLength */
-                              && (forwardPatternLength <= srcPatternLength) ) { /* haven't reached this position yet */
-                                U32 const newMatchIndex = matchCandidateIdx + (U32)forwardPatternLength - (U32)srcPatternLength;  /* best position, full pattern, might be followed by more match */
-                                if (LZ4HC_protectDictEnd(dictLimit, newMatchIndex))
-                                    matchIndex = newMatchIndex;
-                                else {
-                                    /* Can only happen if started in the prefix */
-                                    assert(newMatchIndex >= dictLimit - 3 && newMatchIndex < dictLimit && !extDict);
-                                    matchIndex = dictLimit;
-                                }
-                            } else {
-                                U32 const newMatchIndex = matchCandidateIdx - (U32)backLength;   /* farthest position in current segment, will find a match of length currentSegmentLength + maybe some back */
-                                if (!LZ4HC_protectDictEnd(dictLimit, newMatchIndex)) {
-                                    assert(newMatchIndex >= dictLimit - 3 && newMatchIndex < dictLimit && !extDict);
-                                    matchIndex = dictLimit;
-                                } else {
-                                    matchIndex = newMatchIndex;
-                                    if (lookBackLength==0) {  /* no back possible */
-                                        size_t const maxML = MIN(currentSegmentLength, srcPatternLength);
-                                        if ((size_t)longest < maxML) {
-                                            assert(base + matchIndex < ip);
-                                            if (ip - (base+matchIndex) > LZ4_DISTANCE_MAX) break;
-                                            assert(maxML < 2 GB);
-                                            longest = (int)maxML;
-                                            *matchpos = base + matchIndex;   /* virtual pos, relative to ip, to retrieve offset */
-                                            *startpos = ip;
-                                        }
-                                        {   U32 const distToNextPattern = DELTANEXTU16(chainTable, matchIndex);
-                                            if (distToNextPattern > matchIndex) break;  /* avoid overflow */
-                                            matchIndex -= distToNextPattern;
-                        }   }   }   }   }
-                        continue;
-                }   }
-        }   }   /* PA optimization */
-
-        /* follow current chain */
-        matchIndex -= DELTANEXTU16(chainTable, matchIndex + matchChainPos);
-
-    }  /* while ((matchIndex>=lowestMatchIndex) && (nbAttempts)) */
-
-    if ( dict == usingDictCtxHc
-      && nbAttempts
-      && ipIndex - lowestMatchIndex < LZ4_DISTANCE_MAX) {
-        size_t const dictEndOffset = (size_t)(dictCtx->end - dictCtx->base);
-        U32 dictMatchIndex = dictCtx->hashTable[LZ4HC_hashPtr(ip)];
-        assert(dictEndOffset <= 1 GB);
-        matchIndex = dictMatchIndex + lowestMatchIndex - (U32)dictEndOffset;
-        while (ipIndex - matchIndex <= LZ4_DISTANCE_MAX && nbAttempts--) {
-            const BYTE* const matchPtr = dictCtx->base + dictMatchIndex;
-
-            if (LZ4_read32(matchPtr) == pattern) {
-                int mlt;
-                int back = 0;
-                const BYTE* vLimit = ip + (dictEndOffset - dictMatchIndex);
-                if (vLimit > iHighLimit) vLimit = iHighLimit;
-                mlt = (int)LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, vLimit) + MINMATCH;
-                back = lookBackLength ? LZ4HC_countBack(ip, matchPtr, iLowLimit, dictCtx->base + dictCtx->dictLimit) : 0;
-                mlt -= back;
-                if (mlt > longest) {
-                    longest = mlt;
-                    *matchpos = base + matchIndex + back;
-                    *startpos = ip + back;
-            }   }
-
-            {   U32 const nextOffset = DELTANEXTU16(dictCtx->chainTable, dictMatchIndex);
-                dictMatchIndex -= nextOffset;
-                matchIndex -= nextOffset;
-    }   }   }
-
-    return longest;
-}
-
-LZ4_FORCE_INLINE
-int LZ4HC_InsertAndFindBestMatch(LZ4HC_CCtx_internal* const hc4,   /* Index table will be updated */
-                                 const BYTE* const ip, const BYTE* const iLimit,
-                                 const BYTE** matchpos,
-                                 const int maxNbAttempts,
-                                 const int patternAnalysis,
-                                 const dictCtx_directive dict)
-{
-    const BYTE* uselessPtr = ip;
-    /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos),
-     * but this won't be the case here, as we define iLowLimit==ip,
-     * so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */
-    return LZ4HC_InsertAndGetWiderMatch(hc4, ip, ip, iLimit, MINMATCH-1, matchpos, &uselessPtr, maxNbAttempts, patternAnalysis, 0 /*chainSwap*/, dict, favorCompressionRatio);
-}
-
-/* LZ4HC_encodeSequence() :
- * @return : 0 if ok,
- *           1 if buffer issue detected */
-LZ4_FORCE_INLINE int LZ4HC_encodeSequence (
-    const BYTE** ip,
-    BYTE** op,
-    const BYTE** anchor,
-    int matchLength,
-    const BYTE* const match,
-    limitedOutput_directive limit,
-    BYTE* oend)
-{
-    size_t length;
-    BYTE* const token = (*op)++;
-
-#if defined(LZ4_DEBUG) && (LZ4_DEBUG >= 6)
-    static const BYTE* start = NULL;
-    static U32 totalCost = 0;
-    U32 const pos = (start==NULL) ? 0 : (U32)(*anchor - start);
-    U32 const ll = (U32)(*ip - *anchor);
-    U32 const llAdd = (ll>=15) ? ((ll-15) / 255) + 1 : 0;
-    U32 const mlAdd = (matchLength>=19) ? ((matchLength-19) / 255) + 1 : 0;
-    U32 const cost = 1 + llAdd + ll + 2 + mlAdd;
-    if (start==NULL) start = *anchor;  /* only works for single segment */
-    /* g_debuglog_enable = (pos >= 2228) & (pos <= 2262); */
-    DEBUGLOG(6, "pos:%7u -- literals:%3u, match:%4i, offset:%5u, cost:%3u + %u",
-                pos,
-                (U32)(*ip - *anchor), matchLength, (U32)(*ip-match),
-                cost, totalCost);
-    totalCost += cost;
-#endif
-
-    /* Encode Literal length */
-    length = (size_t)(*ip - *anchor);
-    if ((limit) && ((*op + (length / 255) + length + (2 + 1 + LASTLITERALS)) > oend)) return 1;   /* Check output limit */
-    if (length >= RUN_MASK) {
-        size_t len = length - RUN_MASK;
-        *token = (RUN_MASK << ML_BITS);
-        for(; len >= 255 ; len -= 255) *(*op)++ = 255;
-        *(*op)++ = (BYTE)len;
-    } else {
-        *token = (BYTE)(length << ML_BITS);
-    }
-
-    /* Copy Literals */
-    LZ4_wildCopy8(*op, *anchor, (*op) + length);
-    *op += length;
-
-    /* Encode Offset */
-    assert( (*ip - match) <= LZ4_DISTANCE_MAX );   /* note : consider providing offset as a value, rather than as a pointer difference */
-    LZ4_writeLE16(*op, (U16)(*ip-match)); *op += 2;
-
-    /* Encode MatchLength */
-    assert(matchLength >= MINMATCH);
-    length = (size_t)matchLength - MINMATCH;
-    if ((limit) && (*op + (length / 255) + (1 + LASTLITERALS) > oend)) return 1;   /* Check output limit */
-    if (length >= ML_MASK) {
-        *token += ML_MASK;
-        length -= ML_MASK;
-        for(; length >= 510 ; length -= 510) { *(*op)++ = 255; *(*op)++ = 255; }
-        if (length >= 255) { length -= 255; *(*op)++ = 255; }
-        *(*op)++ = (BYTE)length;
-    } else {
-        *token += (BYTE)(length);
-    }
-
-    /* Prepare next loop */
-    *ip += matchLength;
-    *anchor = *ip;
-
-    return 0;
-}
-
-LZ4_FORCE_INLINE int LZ4HC_compress_hashChain (
-    LZ4HC_CCtx_internal* const ctx,
-    const char* const source,
-    char* const dest,
-    int* srcSizePtr,
-    int const maxOutputSize,
-    unsigned maxNbAttempts,
-    const limitedOutput_directive limit,
-    const dictCtx_directive dict
-    )
-{
-    const int inputSize = *srcSizePtr;
-    const int patternAnalysis = (maxNbAttempts > 128);   /* levels 9+ */
-
-    const BYTE* ip = (const BYTE*) source;
-    const BYTE* anchor = ip;
-    const BYTE* const iend = ip + inputSize;
-    const BYTE* const mflimit = iend - MFLIMIT;
-    const BYTE* const matchlimit = (iend - LASTLITERALS);
-
-    BYTE* optr = (BYTE*) dest;
-    BYTE* op = (BYTE*) dest;
-    BYTE* oend = op + maxOutputSize;
-
-    int   ml0, ml, ml2, ml3;
-    const BYTE* start0;
-    const BYTE* ref0;
-    const BYTE* ref = NULL;
-    const BYTE* start2 = NULL;
-    const BYTE* ref2 = NULL;
-    const BYTE* start3 = NULL;
-    const BYTE* ref3 = NULL;
-
-    /* init */
-    *srcSizePtr = 0;
-    if (limit == fillOutput) oend -= LASTLITERALS;                  /* Hack for support LZ4 format restriction */
-    if (inputSize < LZ4_minLength) goto _last_literals;                  /* Input too small, no compression (all literals) */
-
-    /* Main Loop */
-    while (ip <= mflimit) {
-        ml = LZ4HC_InsertAndFindBestMatch(ctx, ip, matchlimit, &ref, maxNbAttempts, patternAnalysis, dict);
-        if (ml<MINMATCH) { ip++; continue; }
-
-        /* saved, in case we would skip too much */
-        start0 = ip; ref0 = ref; ml0 = ml;
-
-_Search2:
-        if (ip+ml <= mflimit) {
-            ml2 = LZ4HC_InsertAndGetWiderMatch(ctx,
-                            ip + ml - 2, ip + 0, matchlimit, ml, &ref2, &start2,
-                            maxNbAttempts, patternAnalysis, 0, dict, favorCompressionRatio);
-        } else {
-            ml2 = ml;
-        }
-
-        if (ml2 == ml) { /* No better match => encode ML1 */
-            optr = op;
-            if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
-            continue;
-        }
-
-        if (start0 < ip) {   /* first match was skipped at least once */
-            if (start2 < ip + ml0) {  /* squeezing ML1 between ML0(original ML1) and ML2 */
-                ip = start0; ref = ref0; ml = ml0;  /* restore initial ML1 */
-        }   }
-
-        /* Here, start0==ip */
-        if ((start2 - ip) < 3) {  /* First Match too small : removed */
-            ml = ml2;
-            ip = start2;
-            ref =ref2;
-            goto _Search2;
-        }
-
-_Search3:
-        /* At this stage, we have :
-        *  ml2 > ml1, and
-        *  ip1+3 <= ip2 (usually < ip1+ml1) */
-        if ((start2 - ip) < OPTIMAL_ML) {
-            int correction;
-            int new_ml = ml;
-            if (new_ml > OPTIMAL_ML) new_ml = OPTIMAL_ML;
-            if (ip+new_ml > start2 + ml2 - MINMATCH) new_ml = (int)(start2 - ip) + ml2 - MINMATCH;
-            correction = new_ml - (int)(start2 - ip);
-            if (correction > 0) {
-                start2 += correction;
-                ref2 += correction;
-                ml2 -= correction;
-            }
-        }
-        /* Now, we have start2 = ip+new_ml, with new_ml = min(ml, OPTIMAL_ML=18) */
-
-        if (start2 + ml2 <= mflimit) {
-            ml3 = LZ4HC_InsertAndGetWiderMatch(ctx,
-                            start2 + ml2 - 3, start2, matchlimit, ml2, &ref3, &start3,
-                            maxNbAttempts, patternAnalysis, 0, dict, favorCompressionRatio);
-        } else {
-            ml3 = ml2;
-        }
-
-        if (ml3 == ml2) {  /* No better match => encode ML1 and ML2 */
-            /* ip & ref are known; Now for ml */
-            if (start2 < ip+ml)  ml = (int)(start2 - ip);
-            /* Now, encode 2 sequences */
-            optr = op;
-            if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
-            ip = start2;
-            optr = op;
-            if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml2, ref2, limit, oend)) goto _dest_overflow;
-            continue;
-        }
-
-        if (start3 < ip+ml+3) {  /* Not enough space for match 2 : remove it */
-            if (start3 >= (ip+ml)) {  /* can write Seq1 immediately ==> Seq2 is removed, so Seq3 becomes Seq1 */
-                if (start2 < ip+ml) {
-                    int correction = (int)(ip+ml - start2);
-                    start2 += correction;
-                    ref2 += correction;
-                    ml2 -= correction;
-                    if (ml2 < MINMATCH) {
-                        start2 = start3;
-                        ref2 = ref3;
-                        ml2 = ml3;
-                    }
-                }
-
-                optr = op;
-                if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
-                ip  = start3;
-                ref = ref3;
-                ml  = ml3;
-
-                start0 = start2;
-                ref0 = ref2;
-                ml0 = ml2;
-                goto _Search2;
-            }
-
-            start2 = start3;
-            ref2 = ref3;
-            ml2 = ml3;
-            goto _Search3;
-        }
-
-        /*
-        * OK, now we have 3 ascending matches;
-        * let's write the first one ML1.
-        * ip & ref are known; Now decide ml.
-        */
-        if (start2 < ip+ml) {
-            if ((start2 - ip) < OPTIMAL_ML) {
-                int correction;
-                if (ml > OPTIMAL_ML) ml = OPTIMAL_ML;
-                if (ip + ml > start2 + ml2 - MINMATCH) ml = (int)(start2 - ip) + ml2 - MINMATCH;
-                correction = ml - (int)(start2 - ip);
-                if (correction > 0) {
-                    start2 += correction;
-                    ref2 += correction;
-                    ml2 -= correction;
-                }
-            } else {
-                ml = (int)(start2 - ip);
-            }
-        }
-        optr = op;
-        if (LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ref, limit, oend)) goto _dest_overflow;
-
-        /* ML2 becomes ML1 */
-        ip = start2; ref = ref2; ml = ml2;
-
-        /* ML3 becomes ML2 */
-        start2 = start3; ref2 = ref3; ml2 = ml3;
-
-        /* let's find a new ML3 */
-        goto _Search3;
-    }
-
-_last_literals:
-    /* Encode Last Literals */
-    {   size_t lastRunSize = (size_t)(iend - anchor);  /* literals */
-        size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255;
-        size_t const totalSize = 1 + litLength + lastRunSize;
-        if (limit == fillOutput) oend += LASTLITERALS;  /* restore correct value */
-        if (limit && (op + totalSize > oend)) {
-            if (limit == limitedOutput) return 0;  /* Check output limit */
-            /* adapt lastRunSize to fill 'dest' */
-            lastRunSize  = (size_t)(oend - op) - 1;
-            litLength = (lastRunSize + 255 - RUN_MASK) / 255;
-            lastRunSize -= litLength;
-        }
-        ip = anchor + lastRunSize;
-
-        if (lastRunSize >= RUN_MASK) {
-            size_t accumulator = lastRunSize - RUN_MASK;
-            *op++ = (RUN_MASK << ML_BITS);
-            for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255;
-            *op++ = (BYTE) accumulator;
-        } else {
-            *op++ = (BYTE)(lastRunSize << ML_BITS);
-        }
-        memcpy(op, anchor, lastRunSize);
-        op += lastRunSize;
-    }
-
-    /* End */
-    *srcSizePtr = (int) (((const char*)ip) - source);
-    return (int) (((char*)op)-dest);
-
-_dest_overflow:
-    if (limit == fillOutput) {
-        op = optr;  /* restore correct out pointer */
-        goto _last_literals;
-    }
-    return 0;
-}
-
-
-static int LZ4HC_compress_optimal( LZ4HC_CCtx_internal* ctx,
-    const char* const source, char* dst,
-    int* srcSizePtr, int dstCapacity,
-    int const nbSearches, size_t sufficient_len,
-    const limitedOutput_directive limit, int const fullUpdate,
-    const dictCtx_directive dict,
-    HCfavor_e favorDecSpeed);
-
-
-LZ4_FORCE_INLINE int LZ4HC_compress_generic_internal (
-    LZ4HC_CCtx_internal* const ctx,
-    const char* const src,
-    char* const dst,
-    int* const srcSizePtr,
-    int const dstCapacity,
-    int cLevel,
-    const limitedOutput_directive limit,
-    const dictCtx_directive dict
-    )
-{
-    typedef enum { lz4hc, lz4opt } lz4hc_strat_e;
-    typedef struct {
-        lz4hc_strat_e strat;
-        U32 nbSearches;
-        U32 targetLength;
-    } cParams_t;
-    static const cParams_t clTable[LZ4HC_CLEVEL_MAX+1] = {
-        { lz4hc,     2, 16 },  /* 0, unused */
-        { lz4hc,     2, 16 },  /* 1, unused */
-        { lz4hc,     2, 16 },  /* 2, unused */
-        { lz4hc,     4, 16 },  /* 3 */
-        { lz4hc,     8, 16 },  /* 4 */
-        { lz4hc,    16, 16 },  /* 5 */
-        { lz4hc,    32, 16 },  /* 6 */
-        { lz4hc,    64, 16 },  /* 7 */
-        { lz4hc,   128, 16 },  /* 8 */
-        { lz4hc,   256, 16 },  /* 9 */
-        { lz4opt,   96, 64 },  /*10==LZ4HC_CLEVEL_OPT_MIN*/
-        { lz4opt,  512,128 },  /*11 */
-        { lz4opt,16384,LZ4_OPT_NUM },  /* 12==LZ4HC_CLEVEL_MAX */
-    };
-
-    DEBUGLOG(4, "LZ4HC_compress_generic(ctx=%p, src=%p, srcSize=%d)", ctx, src, *srcSizePtr);
-
-    if (limit == fillOutput && dstCapacity < 1) return 0;   /* Impossible to store anything */
-    if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE) return 0;    /* Unsupported input size (too large or negative) */
-
-    ctx->end += *srcSizePtr;
-    if (cLevel < 1) cLevel = LZ4HC_CLEVEL_DEFAULT;   /* note : convention is different from lz4frame, maybe something to review */
-    cLevel = MIN(LZ4HC_CLEVEL_MAX, cLevel);
-    {   cParams_t const cParam = clTable[cLevel];
-        HCfavor_e const favor = ctx->favorDecSpeed ? favorDecompressionSpeed : favorCompressionRatio;
-        int result;
-
-        if (cParam.strat == lz4hc) {
-            result = LZ4HC_compress_hashChain(ctx,
-                                src, dst, srcSizePtr, dstCapacity,
-                                cParam.nbSearches, limit, dict);
-        } else {
-            assert(cParam.strat == lz4opt);
-            result = LZ4HC_compress_optimal(ctx,
-                                src, dst, srcSizePtr, dstCapacity,
-                                (int)cParam.nbSearches, cParam.targetLength, limit,
-                                cLevel == LZ4HC_CLEVEL_MAX,   /* ultra mode */
-                                dict, favor);
-        }
-        if (result <= 0) ctx->dirty = 1;
-        return result;
-    }
-}
-
-static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock);
-
-static int
-LZ4HC_compress_generic_noDictCtx (
-        LZ4HC_CCtx_internal* const ctx,
-        const char* const src,
-        char* const dst,
-        int* const srcSizePtr,
-        int const dstCapacity,
-        int cLevel,
-        limitedOutput_directive limit
-        )
-{
-    assert(ctx->dictCtx == NULL);
-    return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, noDictCtx);
-}
-
-static int
-LZ4HC_compress_generic_dictCtx (
-        LZ4HC_CCtx_internal* const ctx,
-        const char* const src,
-        char* const dst,
-        int* const srcSizePtr,
-        int const dstCapacity,
-        int cLevel,
-        limitedOutput_directive limit
-        )
-{
-    const size_t position = (size_t)(ctx->end - ctx->base) - ctx->lowLimit;
-    assert(ctx->dictCtx != NULL);
-    if (position >= 64 KB) {
-        ctx->dictCtx = NULL;
-        return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
-    } else if (position == 0 && *srcSizePtr > 4 KB) {
-        memcpy(ctx, ctx->dictCtx, sizeof(LZ4HC_CCtx_internal));
-        LZ4HC_setExternalDict(ctx, (const BYTE *)src);
-        ctx->compressionLevel = (short)cLevel;
-        return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
-    } else {
-        return LZ4HC_compress_generic_internal(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit, usingDictCtxHc);
-    }
-}
-
-static int
-LZ4HC_compress_generic (
-        LZ4HC_CCtx_internal* const ctx,
-        const char* const src,
-        char* const dst,
-        int* const srcSizePtr,
-        int const dstCapacity,
-        int cLevel,
-        limitedOutput_directive limit
-        )
-{
-    if (ctx->dictCtx == NULL) {
-        return LZ4HC_compress_generic_noDictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
-    } else {
-        return LZ4HC_compress_generic_dictCtx(ctx, src, dst, srcSizePtr, dstCapacity, cLevel, limit);
-    }
-}
-
-
-int LZ4_sizeofStateHC(void) { return (int)sizeof(LZ4_streamHC_t); }
-
-#ifndef _MSC_VER  /* for some reason, Visual fails the aligment test on 32-bit x86 :
-                   * it reports an aligment of 8-bytes,
-                   * while actually aligning LZ4_streamHC_t on 4 bytes. */
-static size_t LZ4_streamHC_t_alignment(void)
-{
-    struct { char c; LZ4_streamHC_t t; } t_a;
-    return sizeof(t_a) - sizeof(t_a.t);
-}
-#endif
-
-/* state is presumed correctly initialized,
- * in which case its size and alignment have already been validate */
-static int LZ4_compress_HC_extStateHC_fastReset (void* state, const char* src, char* dst, int srcSize,
-						 int dstCapacity, int compressionLevel)
-{
-    LZ4HC_CCtx_internal* const ctx = &((LZ4_streamHC_t*)state)->internal_donotuse;
-#ifndef _MSC_VER  /* for some reason, Visual fails the aligment test on 32-bit x86 :
-                   * it reports an aligment of 8-bytes,
-                   * while actually aligning LZ4_streamHC_t on 4 bytes. */
-    assert(((size_t)state & (LZ4_streamHC_t_alignment() - 1)) == 0);  /* check alignment */
-#endif
-    if (((size_t)(state)&(sizeof(void*)-1)) != 0) return 0;   /* Error : state is not aligned for pointers (32 or 64 bits) */
-    LZ4_resetStreamHC_fast((LZ4_streamHC_t*)state, compressionLevel);
-    LZ4HC_init_internal (ctx, (const BYTE*)src);
-    if (dstCapacity < LZ4_compressBound(srcSize))
-        return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, limitedOutput);
-    else
-        return LZ4HC_compress_generic (ctx, src, dst, &srcSize, dstCapacity, compressionLevel, notLimited);
-}
-
-int LZ4_compress_HC_extStateHC (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
-{
-    LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx));
-    if (ctx==NULL) return 0;   /* init failure */
-    return LZ4_compress_HC_extStateHC_fastReset(state, src, dst, srcSize, dstCapacity, compressionLevel);
-}
-
-int LZ4_compress_HC(const char* src, char* dst, int srcSize, int dstCapacity, int compressionLevel)
-{
-#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
-    LZ4_streamHC_t* const statePtr = (LZ4_streamHC_t*)ALLOC(sizeof(LZ4_streamHC_t));
-#else
-    LZ4_streamHC_t state;
-    LZ4_streamHC_t* const statePtr = &state;
-#endif
-    int const cSize = LZ4_compress_HC_extStateHC(statePtr, src, dst, srcSize, dstCapacity, compressionLevel);
-#if defined(LZ4HC_HEAPMODE) && LZ4HC_HEAPMODE==1
-    FREEMEM(statePtr);
-#endif
-    return cSize;
-}
-
-/* state is presumed sized correctly (>= sizeof(LZ4_streamHC_t)) */
-int LZ4_compress_HC_destSize(void* state, const char* source, char* dest, int* sourceSizePtr, int targetDestSize, int cLevel)
-{
-    LZ4_streamHC_t* const ctx = LZ4_initStreamHC(state, sizeof(*ctx));
-    if (ctx==NULL) return 0;   /* init failure */
-    LZ4HC_init_internal(&ctx->internal_donotuse, (const BYTE*) source);
-    LZ4_setCompressionLevel(ctx, cLevel);
-    return LZ4HC_compress_generic(&ctx->internal_donotuse, source, dest, sourceSizePtr, targetDestSize, cLevel, fillOutput);
-}
-
-
-
-/**************************************
-*  Streaming Functions
-**************************************/
-
-LZ4_streamHC_t* LZ4_initStreamHC (void* buffer, size_t size)
-{
-    LZ4_streamHC_t* const LZ4_streamHCPtr = (LZ4_streamHC_t*)buffer;
-    if (buffer == NULL) return NULL;
-    if (size < sizeof(LZ4_streamHC_t)) return NULL;
-#ifndef _MSC_VER  /* for some reason, Visual fails the aligment test on 32-bit x86 :
-                   * it reports an aligment of 8-bytes,
-                   * while actually aligning LZ4_streamHC_t on 4 bytes. */
-    if (((size_t)buffer) & (LZ4_streamHC_t_alignment() - 1)) return NULL;  /* alignment check */
-#endif
-    /* if compilation fails here, LZ4_STREAMHCSIZE must be increased */
-    LZ4_STATIC_ASSERT(sizeof(LZ4HC_CCtx_internal) <= LZ4_STREAMHCSIZE);
-    DEBUGLOG(4, "LZ4_initStreamHC(%p, %u)", LZ4_streamHCPtr, (unsigned)size);
-    /* end-base will trigger a clearTable on starting compression */
-    LZ4_streamHCPtr->internal_donotuse.end = (const BYTE *)(ptrdiff_t)-1;
-    LZ4_streamHCPtr->internal_donotuse.base = NULL;
-    LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
-    LZ4_streamHCPtr->internal_donotuse.favorDecSpeed = 0;
-    LZ4_streamHCPtr->internal_donotuse.dirty = 0;
-    LZ4_setCompressionLevel(LZ4_streamHCPtr, LZ4HC_CLEVEL_DEFAULT);
-    return LZ4_streamHCPtr;
-}
-
-/* just a stub */
-void LZ4_resetStreamHC_fast (LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
-{
-    DEBUGLOG(4, "LZ4_resetStreamHC_fast(%p, %d)", LZ4_streamHCPtr, compressionLevel);
-    if (LZ4_streamHCPtr->internal_donotuse.dirty) {
-        LZ4_initStreamHC(LZ4_streamHCPtr, sizeof(*LZ4_streamHCPtr));
-    } else {
-        /* preserve end - base : can trigger clearTable's threshold */
-        LZ4_streamHCPtr->internal_donotuse.end -= (uptrval)LZ4_streamHCPtr->internal_donotuse.base;
-        LZ4_streamHCPtr->internal_donotuse.base = NULL;
-        LZ4_streamHCPtr->internal_donotuse.dictCtx = NULL;
-    }
-    LZ4_setCompressionLevel(LZ4_streamHCPtr, compressionLevel);
-}
-
-void LZ4_setCompressionLevel(LZ4_streamHC_t* LZ4_streamHCPtr, int compressionLevel)
-{
-    DEBUGLOG(5, "LZ4_setCompressionLevel(%p, %d)", LZ4_streamHCPtr, compressionLevel);
-    if (compressionLevel < 1) compressionLevel = LZ4HC_CLEVEL_DEFAULT;
-    if (compressionLevel > LZ4HC_CLEVEL_MAX) compressionLevel = LZ4HC_CLEVEL_MAX;
-    LZ4_streamHCPtr->internal_donotuse.compressionLevel = (short)compressionLevel;
-}
-
-/* compression */
-
-static void LZ4HC_setExternalDict(LZ4HC_CCtx_internal* ctxPtr, const BYTE* newBlock)
-{
-    DEBUGLOG(4, "LZ4HC_setExternalDict(%p, %p)", ctxPtr, newBlock);
-    if (ctxPtr->end >= ctxPtr->base + ctxPtr->dictLimit + 4)
-        LZ4HC_Insert (ctxPtr, ctxPtr->end-3);   /* Referencing remaining dictionary content */
-
-    /* Only one memory segment for extDict, so any previous extDict is lost at this stage */
-    ctxPtr->lowLimit  = ctxPtr->dictLimit;
-    ctxPtr->dictLimit = (U32)(ctxPtr->end - ctxPtr->base);
-    ctxPtr->dictBase  = ctxPtr->base;
-    ctxPtr->base = newBlock - ctxPtr->dictLimit;
-    ctxPtr->end  = newBlock;
-    ctxPtr->nextToUpdate = ctxPtr->dictLimit;   /* match referencing will resume from there */
-
-    /* cannot reference an extDict and a dictCtx at the same time */
-    ctxPtr->dictCtx = NULL;
-}
-
-/* ================================================
- *  LZ4 Optimal parser (levels [LZ4HC_CLEVEL_OPT_MIN - LZ4HC_CLEVEL_MAX])
- * ===============================================*/
-typedef struct {
-    int price;
-    int off;
-    int mlen;
-    int litlen;
-} LZ4HC_optimal_t;
-
-/* price in bytes */
-LZ4_FORCE_INLINE int LZ4HC_literalsPrice(int const litlen)
-{
-    int price = litlen;
-    assert(litlen >= 0);
-    if (litlen >= (int)RUN_MASK)
-        price += 1 + ((litlen-(int)RUN_MASK) / 255);
-    return price;
-}
-
-
-/* requires mlen >= MINMATCH */
-LZ4_FORCE_INLINE int LZ4HC_sequencePrice(int litlen, int mlen)
-{
-    int price = 1 + 2 ; /* token + 16-bit offset */
-    assert(litlen >= 0);
-    assert(mlen >= MINMATCH);
-
-    price += LZ4HC_literalsPrice(litlen);
-
-    if (mlen >= (int)(ML_MASK+MINMATCH))
-        price += 1 + ((mlen-(int)(ML_MASK+MINMATCH)) / 255);
-
-    return price;
-}
-
-
-typedef struct {
-    int off;
-    int len;
-} LZ4HC_match_t;
-
-LZ4_FORCE_INLINE LZ4HC_match_t
-LZ4HC_FindLongerMatch(LZ4HC_CCtx_internal* const ctx,
-                      const BYTE* ip, const BYTE* const iHighLimit,
-                      int minLen, int nbSearches,
-                      const dictCtx_directive dict,
-                      const HCfavor_e favorDecSpeed)
-{
-    LZ4HC_match_t match = { 0 , 0 };
-    const BYTE* matchPtr = NULL;
-    /* note : LZ4HC_InsertAndGetWiderMatch() is able to modify the starting position of a match (*startpos),
-     * but this won't be the case here, as we define iLowLimit==ip,
-     * so LZ4HC_InsertAndGetWiderMatch() won't be allowed to search past ip */
-    int matchLength = LZ4HC_InsertAndGetWiderMatch(ctx, ip, ip, iHighLimit, minLen, &matchPtr, &ip, nbSearches, 1 /*patternAnalysis*/, 1 /*chainSwap*/, dict, favorDecSpeed);
-    if (matchLength <= minLen) return match;
-    if (favorDecSpeed) {
-        if ((matchLength>18) & (matchLength<=36)) matchLength=18;   /* favor shortcut */
-    }
-    match.len = matchLength;
-    match.off = (int)(ip-matchPtr);
-    return match;
-}
-
-
-static int LZ4HC_compress_optimal ( LZ4HC_CCtx_internal* ctx,
-                                    const char* const source,
-                                    char* dst,
-                                    int* srcSizePtr,
-                                    int dstCapacity,
-                                    int const nbSearches,
-                                    size_t sufficient_len,
-                                    const limitedOutput_directive limit,
-                                    int const fullUpdate,
-                                    const dictCtx_directive dict,
-                                    const HCfavor_e favorDecSpeed)
-{
-#define TRAILING_LITERALS 3
-    LZ4HC_optimal_t opt[LZ4_OPT_NUM + TRAILING_LITERALS];   /* ~64 KB, which is a bit large for stack... */
-
-    const BYTE* ip = (const BYTE*) source;
-    const BYTE* anchor = ip;
-    const BYTE* const iend = ip + *srcSizePtr;
-    const BYTE* const mflimit = iend - MFLIMIT;
-    const BYTE* const matchlimit = iend - LASTLITERALS;
-    BYTE* op = (BYTE*) dst;
-    BYTE* opSaved = (BYTE*) dst;
-    BYTE* oend = op + dstCapacity;
-
-    /* init */
-    DEBUGLOG(5, "LZ4HC_compress_optimal(dst=%p, dstCapa=%u)", dst, (unsigned)dstCapacity);
-    *srcSizePtr = 0;
-    if (limit == fillOutput) oend -= LASTLITERALS;   /* Hack for support LZ4 format restriction */
-    if (sufficient_len >= LZ4_OPT_NUM) sufficient_len = LZ4_OPT_NUM-1;
-
-    /* Main Loop */
-    assert(ip - anchor < LZ4_MAX_INPUT_SIZE);
-    while (ip <= mflimit) {
-         int const llen = (int)(ip - anchor);
-         int best_mlen, best_off;
-         int cur, last_match_pos = 0;
-
-         LZ4HC_match_t const firstMatch = LZ4HC_FindLongerMatch(ctx, ip, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed);
-         if (firstMatch.len==0) { ip++; continue; }
-
-         if ((size_t)firstMatch.len > sufficient_len) {
-             /* good enough solution : immediate encoding */
-             int const firstML = firstMatch.len;
-             const BYTE* const matchPos = ip - firstMatch.off;
-             opSaved = op;
-             if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), firstML, matchPos, limit, oend) )   /* updates ip, op and anchor */
-                 goto _dest_overflow;
-             continue;
-         }
-
-         /* set prices for first positions (literals) */
-         {   int rPos;
-             for (rPos = 0 ; rPos < MINMATCH ; rPos++) {
-                 int const cost = LZ4HC_literalsPrice(llen + rPos);
-                 opt[rPos].mlen = 1;
-                 opt[rPos].off = 0;
-                 opt[rPos].litlen = llen + rPos;
-                 opt[rPos].price = cost;
-                 DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup",
-                             rPos, cost, opt[rPos].litlen);
-         }   }
-         /* set prices using initial match */
-         {   int mlen = MINMATCH;
-             int const matchML = firstMatch.len;   /* necessarily < sufficient_len < LZ4_OPT_NUM */
-             int const offset = firstMatch.off;
-             assert(matchML < LZ4_OPT_NUM);
-             for ( ; mlen <= matchML ; mlen++) {
-                 int const cost = LZ4HC_sequencePrice(llen, mlen);
-                 opt[mlen].mlen = mlen;
-                 opt[mlen].off = offset;
-                 opt[mlen].litlen = llen;
-                 opt[mlen].price = cost;
-                 DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i) -- initial setup",
-                             mlen, cost, mlen);
-         }   }
-         last_match_pos = firstMatch.len;
-         {   int addLit;
-             for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) {
-                 opt[last_match_pos+addLit].mlen = 1; /* literal */
-                 opt[last_match_pos+addLit].off = 0;
-                 opt[last_match_pos+addLit].litlen = addLit;
-                 opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit);
-                 DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i) -- initial setup",
-                             last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit);
-         }   }
-
-         /* check further positions */
-         for (cur = 1; cur < last_match_pos; cur++) {
-             const BYTE* const curPtr = ip + cur;
-             LZ4HC_match_t newMatch;
-
-             if (curPtr > mflimit) break;
-             DEBUGLOG(7, "rPos:%u[%u] vs [%u]%u",
-                     cur, opt[cur].price, opt[cur+1].price, cur+1);
-             if (fullUpdate) {
-                 /* not useful to search here if next position has same (or lower) cost */
-                 if ( (opt[cur+1].price <= opt[cur].price)
-                   /* in some cases, next position has same cost, but cost rises sharply after, so a small match would still be beneficial */
-                   && (opt[cur+MINMATCH].price < opt[cur].price + 3/*min seq price*/) )
-                     continue;
-             } else {
-                 /* not useful to search here if next position has same (or lower) cost */
-                 if (opt[cur+1].price <= opt[cur].price) continue;
-             }
-
-             DEBUGLOG(7, "search at rPos:%u", cur);
-             if (fullUpdate)
-                 newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, MINMATCH-1, nbSearches, dict, favorDecSpeed);
-             else
-                 /* only test matches of minimum length; slightly faster, but misses a few bytes */
-                 newMatch = LZ4HC_FindLongerMatch(ctx, curPtr, matchlimit, last_match_pos - cur, nbSearches, dict, favorDecSpeed);
-             if (!newMatch.len) continue;
-
-             if ( ((size_t)newMatch.len > sufficient_len)
-               || (newMatch.len + cur >= LZ4_OPT_NUM) ) {
-                 /* immediate encoding */
-                 best_mlen = newMatch.len;
-                 best_off = newMatch.off;
-                 last_match_pos = cur + 1;
-                 goto encode;
-             }
-
-             /* before match : set price with literals at beginning */
-             {   int const baseLitlen = opt[cur].litlen;
-                 int litlen;
-                 for (litlen = 1; litlen < MINMATCH; litlen++) {
-                     int const price = opt[cur].price - LZ4HC_literalsPrice(baseLitlen) + LZ4HC_literalsPrice(baseLitlen+litlen);
-                     int const pos = cur + litlen;
-                     if (price < opt[pos].price) {
-                         opt[pos].mlen = 1; /* literal */
-                         opt[pos].off = 0;
-                         opt[pos].litlen = baseLitlen+litlen;
-                         opt[pos].price = price;
-                         DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)",
-                                     pos, price, opt[pos].litlen);
-             }   }   }
-
-             /* set prices using match at position = cur */
-             {   int const matchML = newMatch.len;
-                 int ml = MINMATCH;
-
-                 assert(cur + newMatch.len < LZ4_OPT_NUM);
-                 for ( ; ml <= matchML ; ml++) {
-                     int const pos = cur + ml;
-                     int const offset = newMatch.off;
-                     int price;
-                     int ll;
-                     DEBUGLOG(7, "testing price rPos %i (last_match_pos=%i)",
-                                 pos, last_match_pos);
-                     if (opt[cur].mlen == 1) {
-                         ll = opt[cur].litlen;
-                         price = ((cur > ll) ? opt[cur - ll].price : 0)
-                               + LZ4HC_sequencePrice(ll, ml);
-                     } else {
-                         ll = 0;
-                         price = opt[cur].price + LZ4HC_sequencePrice(0, ml);
-                     }
-
-                    assert((U32)favorDecSpeed <= 1);
-                     if (pos > last_match_pos+TRAILING_LITERALS
-                      || price <= opt[pos].price - (int)favorDecSpeed) {
-                         DEBUGLOG(7, "rPos:%3i => price:%3i (matchlen=%i)",
-                                     pos, price, ml);
-                         assert(pos < LZ4_OPT_NUM);
-                         if ( (ml == matchML)  /* last pos of last match */
-                           && (last_match_pos < pos) )
-                             last_match_pos = pos;
-                         opt[pos].mlen = ml;
-                         opt[pos].off = offset;
-                         opt[pos].litlen = ll;
-                         opt[pos].price = price;
-             }   }   }
-             /* complete following positions with literals */
-             {   int addLit;
-                 for (addLit = 1; addLit <= TRAILING_LITERALS; addLit ++) {
-                     opt[last_match_pos+addLit].mlen = 1; /* literal */
-                     opt[last_match_pos+addLit].off = 0;
-                     opt[last_match_pos+addLit].litlen = addLit;
-                     opt[last_match_pos+addLit].price = opt[last_match_pos].price + LZ4HC_literalsPrice(addLit);
-                     DEBUGLOG(7, "rPos:%3i => price:%3i (litlen=%i)", last_match_pos+addLit, opt[last_match_pos+addLit].price, addLit);
-             }   }
-         }  /* for (cur = 1; cur <= last_match_pos; cur++) */
-
-         assert(last_match_pos < LZ4_OPT_NUM + TRAILING_LITERALS);
-         best_mlen = opt[last_match_pos].mlen;
-         best_off = opt[last_match_pos].off;
-         cur = last_match_pos - best_mlen;
-
- encode: /* cur, last_match_pos, best_mlen, best_off must be set */
-         assert(cur < LZ4_OPT_NUM);
-         assert(last_match_pos >= 1);  /* == 1 when only one candidate */
-         DEBUGLOG(6, "reverse traversal, looking for shortest path (last_match_pos=%i)", last_match_pos);
-         {   int candidate_pos = cur;
-             int selected_matchLength = best_mlen;
-             int selected_offset = best_off;
-             while (1) {  /* from end to beginning */
-                 int const next_matchLength = opt[candidate_pos].mlen;  /* can be 1, means literal */
-                 int const next_offset = opt[candidate_pos].off;
-                 DEBUGLOG(7, "pos %i: sequence length %i", candidate_pos, selected_matchLength);
-                 opt[candidate_pos].mlen = selected_matchLength;
-                 opt[candidate_pos].off = selected_offset;
-                 selected_matchLength = next_matchLength;
-                 selected_offset = next_offset;
-                 if (next_matchLength > candidate_pos) break; /* last match elected, first match to encode */
-                 assert(next_matchLength > 0);  /* can be 1, means literal */
-                 candidate_pos -= next_matchLength;
-         }   }
-
-         /* encode all recorded sequences in order */
-         {   int rPos = 0;  /* relative position (to ip) */
-             while (rPos < last_match_pos) {
-                 int const ml = opt[rPos].mlen;
-                 int const offset = opt[rPos].off;
-                 if (ml == 1) { ip++; rPos++; continue; }  /* literal; note: can end up with several literals, in which case, skip them */
-                 rPos += ml;
-                 assert(ml >= MINMATCH);
-                 assert((offset >= 1) && (offset <= LZ4_DISTANCE_MAX));
-                 opSaved = op;
-                 if ( LZ4HC_encodeSequence(UPDATABLE(ip, op, anchor), ml, ip - offset, limit, oend) )   /* updates ip, op and anchor */
-                     goto _dest_overflow;
-         }   }
-     }  /* while (ip <= mflimit) */
-
- _last_literals:
-     /* Encode Last Literals */
-     {   size_t lastRunSize = (size_t)(iend - anchor);  /* literals */
-         size_t litLength = (lastRunSize + 255 - RUN_MASK) / 255;
-         size_t const totalSize = 1 + litLength + lastRunSize;
-         if (limit == fillOutput) oend += LASTLITERALS;  /* restore correct value */
-         if (limit && (op + totalSize > oend)) {
-             if (limit == limitedOutput) return 0;  /* Check output limit */
-             /* adapt lastRunSize to fill 'dst' */
-             lastRunSize  = (size_t)(oend - op) - 1;
-             litLength = (lastRunSize + 255 - RUN_MASK) / 255;
-             lastRunSize -= litLength;
-         }
-         ip = anchor + lastRunSize;
-
-         if (lastRunSize >= RUN_MASK) {
-             size_t accumulator = lastRunSize - RUN_MASK;
-             *op++ = (RUN_MASK << ML_BITS);
-             for(; accumulator >= 255 ; accumulator -= 255) *op++ = 255;
-             *op++ = (BYTE) accumulator;
-         } else {
-             *op++ = (BYTE)(lastRunSize << ML_BITS);
-         }
-         memcpy(op, anchor, lastRunSize);
-         op += lastRunSize;
-     }
-
-     /* End */
-     *srcSizePtr = (int) (((const char*)ip) - source);
-     return (int) ((char*)op-dst);
-
- _dest_overflow:
-     if (limit == fillOutput) {
-         op = opSaved;  /* restore correct out pointer */
-         goto _last_literals;
-     }
-     return 0;
- }